Mel Gibson is now legally single after his divorce was finalized Friday in a Los Angeles courtroom, but bachelorhood came at a heavy price.

Robyn, his ex-wife of nearly 30 years and the mother of their seven children, is walking away with half his fortune, once estimated to be as high as $850 million (according to the Los Angeles Business Journal in 2006) in what is considered the biggest divorce payout in Hollywood history.

Because the couple didn't have a prenuptial agreement, Robyn, 55, was legally entitled to half of everything he earned during their marriage.

Among Gibson's estimated assets: more than $600 million grossed by The Passion of the Christ alone; $100-plus million in real estate investments worldwide (he bought an island in Fiji for $15 million in 2005); and $75 million for film and TV projects for which Gibson, 55, executive produced.

It appears some of his wealth has already been transferred to Robyn, in particular two Malibu homes worth a combined $22.5 million. As for film residuals, Robyn is entitled to half of every future check Gibson receives for the rest of his life.

"I left my wife because we had no spiritual common ground," Gibson told his then-girlfriend Oksana Grigorieva in secretly recorded tapes she made of the actor in February 2010.

During his custody battle with Grigorieva, in which the Russian musician accused Gibson of domestic violence, Robyn filed a sworn statement in July 2010 stating that "Mel was a wonderful and loving father" and never abused Robyn or their kids.

Gibson met Robyn, at the time a dental nurse, in the late 1970s after the American-born actor, who moved to Australia when he was 12, had filmed his breakout role in Mad Max.